Arc-lamp.



G. A. B HALVORSON; JR,

ABC mm APPLICATION FILED JAR. 28,19D9.

' 973,653. Patented 0ct.25,11@.

' I Fig. i.

J4 v 55 1, I isv i 3r J6 i v Iriventom Cromwei l H. B. Haiyarscm Jr UNYTED STATES PATENT OFFICE.

GROMWELL A. B. HALVORSON, JR., OF SAUGUS, MASSACHUSETTS,,ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A. CORPORATION OF NEW YORK.

ARC-LAMP.

Specification of Letters Patent.

Patented Oct. 25, 1910.

Application filed January 28, 1909. Serial No. 474,721.

' Lamps, of which the following is a specification.

My invention has reference to improvements in arc lamps of the kind in which for the establishment of the arc and also at intervals during the feeding operation the two electrodes are brought together and are then separated to the arcing distance. In these lamps cathodes are employed which in consuming yield the gases or vapors which maintain the arc, while the anode is, as a rule, a piece of metal of good conductivity of heat and electricity and which, theoretically speaking, is not at all consumed, although in practice it has proved to become consumed at a slow rate. The cathode is usually made of a material which becomes fused at the arcing end, forming there a little pool from which the arc springs' In these lamps the inconvenience has been experienced that when the cathode, which is usually the lower electrode, is forcibly brought into contact with the anode the two electrodes become super'ficially fused togeth'cr, and this phenomenon is spoken of as the freezing together of the electrodes. When this happens the electrodes are held together so tenaciously that they cannot be separated and the arc cannot be established, and the unduly great amount of current which is thus allowed to pass is liable to injure the parts.

My invention is designed to overcome this freezing together of the electrodes, and it consists in a peculiar mounting .of one of the electrodes in such manner that when during the feeding operation the two electrodes are brought forcibly together one of these electrodes is caused to turn upon a pivotal pointso as to be out of alinement with the other electrode, whereby the arcing faces of the two electrodes form a considerable angle with each other so as to be out of contact throughout their greater part, whereby the fused pool of the cathode is prevented from sticking to the anode or, if it has temporarily stuck to the same, is again peeled off before the pool has congealed and bardened. All thiswill more fully appear from the following description with reference to the accompanying drawing, in which:

Figure 1 represents an elevation of the operating mechanism of an electric arc lamp of the kind to which my invention applies, with its circuit connections and electromagnets diagrammatically indicated, the electrodes being shown separated; and Fig. 2 represents a portion of the same lamp mechanism inthe condition after the electrodes have come into contact.

.Like numerals, of reference indicate like parts throughout the drawing.

In these drawings, 1. and 2 represent respectively a positive and a negative electrode of a luminous arc lamp. The positive e1ec-- trodel is shown in the form of a copper rod having wing-like extensions-3, 4 which pass through diametrically opposite slots 5, 6 in the walls of the fume box 7. In these'slots the wings of the electrode can move up and downbut normally rest upon cotter pins 8, 9

whichpass through flanges 10, 11 extending from the fume boX nea-rthe slots :5, 6. Then the wings of the electrode l-rest upon these cotter pins the wings themselves are horizontal and the electrode 1 is vertical and in axial alinement with the electrode 2, as

shown in Fig. 1. In accordance with my invention the slots 5, 6 are made of unequallength, as is clearly indicated in the drawing in which the slot 6 is shown as extending considerably higher up into v the wall of the fume box than the slot and this is the special feature of-my invention as embodied in a lamp of the character here illustrated,

as .will appear farther on- The platform 12 supports the fume box and fromthe upper side of the platform ex- I tends a chimneyv 13, it being understood that ported and operated in a well-known manner. The tube 14 passes vertically through the platform and through the guide tube 15 and carriesat- ,its lower end'anarm 10 which terminates in a socket 17 inwhich the negative electrode is clam ed. The tube i lis guided at its upper end y a rod 18 which projects downward from a bracket 19 supported by a standard 20 which is mounted on a plate 21 insulated from the platform 1.2.

22 and 23 are the lifting and holding clutches, of any usual construction. The function of the lifting clutch is to engage the supporting tube of the lower electrode and move it vertically until this electrode has come into forcible engagement with the upper electrode. vThe function of the holding clutch is to cotiperate with the support for the lower electrode so as to permit this electrode to drop a. predetermined distance away from the upper electrode after the two elec trodes have been brought into engagement by means of the lifting clutch. The lifting clutch is operat'cdby a. suitable regulating magnet having an armature 2 1- and an ener- I v .'J' I gizing co1l 2o, and this magnet- 1s so coir trolled, astofbecome deenergized after the two; electrodes have come into engagement and thus permit the separation of the electrodes for the" establish ment of the arc. The core of the electromagnet has attached to its yoke a stein 26 provided with a collar 27 upon which the end of the pawl arm 28 of the lifting clutch 22 rests. When the magnet is energized the core is drawn upward, thelifting clutch is brought into operative engagement with the tubular portion 14: of the carricr of the lower electrode and is then carried vertically upward until the lower electrode is brought into engagement with the upper electrode. The hold ing clutch 23 is of the usual floating type, normally locked to the tubular support of the lower electrode by means of the long spring 29, the upper end' of which is hooked to the bracket 19 and the lower end to the pawl 30 of the clutch 28f Normally this clutch rests upon the fixed stop 31 rising from the-insulated plate or platform 21. Then the lifting movement begins, the holding clutch travelswith the" electrode-carrying tube it until it comes intofengagcment with a second stop 32 which is arranged at some distance above the stop 31. The position of the stop 32 may be adjusted to the desired hcightjabove -thc stop ill on the rod 20' in any suitable manner. 'lhisstopfll arrests the upwardv .mo'vcmcnt of the holding clutch which, however, permits the clcctrode-supporting tube to continue its upward movement, since by the engagement of this clutch with the stop 32 the clutch releases the tube 14. When the" electroniagnet is deenergized, the lower elecning of the operation when current is turned on and at each feedingoperat on',"

trode and its supporting tube begin to drop, but the holding clutch immediately again grips the tube 1.4: and is carried downward with it until it again strikes thctstopfil,

when both the clutch and electrode are brought to rest.

movable member 33 of this dashpot being connected to the stem 26, while the station ary member is fixed to the platform 12.

In Fig. 1 the parts are shown in the nor- Thc dashpot controls the. speed of descent of the lower'electrode; the

mal running position of the lamp, which'is" also the position when the current is turned off from the lamp.

In addition to the main magnet, there are with the coil of the main magnet.

are attached contacts 36, 37 which,,when

they engage, place a shunt around the coil -w of the clcctromagnet'35 and connectthe coil.

of the main magnet across the line iILSGw,

ries with the resistancc38. When both magnets 34:, 35 are de inergized the contacts 36, '37 engage, while during the .subsequentde;

energization of magnet 35 and the energize} tion of magnet 34 the contacts are out of,

engagement; When current is thrown-comm I the contacts 36, 3Zbe1ng 111 engagemenha circuit is established through the n ain elec-,,= troniagnet while the electromagnetfi5 remains deenergized. The lower electrode 2 is, therefore, raised in the manner hereinbefore described until it engages wlththejup Current now flows through per electrode.

the electrodes in series With-the coil of electromagnet 34, and this magne't being ener gized lifts the contact 36 out of enga ement with'contact 37 thereby connecting t ejcoil of magnet 35 in series with the coil of the main magnet.

The current through the main magnet is now so diminished that; its

armature drops, freeing the tube 1fi, which now also drops, carrying with it the lower electrode". As the .arc lengthens magnet 34:v becomes weaker and magnet stronger until a. point is reached when the contacts 36, 37 are'brought together; whereupon the main magnetis again operatively energized and the lower electrode is lifted as before.

The lamp so-far described is of a well,-

known construction, and I have here dcscribed this lamp only asexemplifying the general character of lamp to which in invention appl es; namely, as one 111 wine the lower electrode is brought lnto fOIGlblG contact with" the upper electrode and is then allowed to drop away from the same for the:

establislnnentyof the arc, both in the be inr st and it is during these feeding operations that the phenomenon of welding or freezing together of the electrodes frequently happens, and which my invention is designed to avoid. It will readily be understood that when the lower electrode is forcibly thrown up into engagement with the upper electrode at a time when a molten pool has formed at the arcing end of either electrode, but gen; erally at the face of the lower electrode, and if the upper electrode were either fixed in position or were guided so that it would after contact with the lower electrode move upwardly in axial alinement with the same, the molten pool would superficially fuse the surface of the upper electrode, and, since the arc at that time is extinguished, the pool would congeal and hold the two electrodes together, so that they could not be separated for the reestablishment of the are. This is the phenomenon which actually happens in lamps of this general character. With the construction herein shown this welding or freezing is avoided because, by reason of the unequal height of thetwo slots 5, 6 in which the wings 3, 4 of the upper electrode are guided, this upper electrode, when thrown upwardly by the impingement of the lower electrode therewith, will move upwardly in axial alinement with the lower electrode only'an extremely short distance; namely, until the upper edge ofthe wing 3 is arrest-ed by the upper end of the slot 5. After this the upper'electrode continues to move upwardly, but no longer in axial alinement with the lower electrode, but inclined to that axis, since the upper end of the slot 5 now acts as a pivot for the electrode 1 upon which the same turns. upwardly until the upper edge of the wing 4 comes into contact with the upper end of the slot 6, which is at a considerably higher level than the upper end of the slot 5. The position of the two electrodes durin this phase of the operation is clearly in icated in I ig. 2, where it is seen that the arcing faces of the two electrodes are out of cont-act throughout their greater part and are only in contact at a point at their edges. Therefore, if during the initial upward movement of the two electrodes it should happen that the molten pool in the arcing face of the lower electrode incipiently fuses to the upper electrode, this incipient fusion will instantly be broken by the subsequent angular movement of the upper electrode; the fusion is, so to speak, peeled off, and the two electrodes be- I come again as free from each other as before contact between them' was established. I have found that by this arrangement the welding, sticking, or freezing together of the two electrodes is effectively prevented; and it will be clear from the foregoing descri tion that I am not confined to the identica construction herein shown and de the welding of the electrodes, and the greater this deviatlon from the axial alinement or from parallelism of the arcmgfaces is made and the more promptly'it is produced, the

more surely will the welding of the electrodes be prevented.

While in the foregoing description and in the drawin I have explained and illustrated my invention with reference to a lamp in which the electrodes are apart when the current is off, it is quite evidentthat the mvention'is equally applicable to lamps in which the electrodes are in cont-act when the current is off.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent,-is:

1. In an arc lamp with electrodes having weldable contactin surfaces, means for con tactlng the GIBCtIOtiS and bodily moving one of them and then separating them for establishing the arc, and means for angularly displacing one arcing face with reference to the other during contact.

2. In an arc lamp with weldable electrodes, means for forcibly impacting the electrodes and bodily moving one of them and then separating them for establishing the arc, and means for angularly separating the arcing faces by the force of the impact.

3. In an arc lamp with weldable electrodes, means for forcibly impacting the electrodes and bodily moving one of them and then separating them for establishing the arc, and means for turning the arcing face of one electrode at an angle to the face of and by the impact of the other electrode.

4. In an arc lamp with weldable electrodes, means .forfeeding one electrode into forcible contactwith the other and moving it bodily and then separating them for establishing the arc, and means for tilting the arcing face of one of the electrodes by the force of the contact with the other.

In an arc lamp, a positive metal electrode normally maintained in predetermined position, a negative electrode of a ma terial developing a fusedfpool in itsarcing face under the action of the arc, means for moving the negative electrode into contact with the positive electrode and then separating it therefrom to strike the arc, and means for bodily lifting and simultaneously tilting the face of the positive electrodeiron'i the fused pool during contact.

6. In an arc lamp, the combination of an upper electrode, two vertical guides of unequal height affording freedom of upward movement for the electrode, a lower elec-- trode, and means for feeding it into contact with the upper electrode and tilting the lab means for feedln the same into contact, ter about the upper end of the guule of 'wlth the upper e ectrode and forcing the lesser height. Whigs of the letter each to the upper end of 7.1m an arc lamp a draft tube hevmg Its guld lng slot. a5. diametrically opposite vertical slots of un- In wltness whereef, I have hereunto set 15 equal, height, a winged upper electrode m hand. this twelfth day of January 1909.

whose Wings freely extend threughihe slots, l GROMWELL A. B. HALVGRSON, J

' means for normally supporting the elec l l Vitneeses: I trode with its Wings in e predetermined her- I JOHN A. lWCBQANUB, J12, .10 ,inc-ntal w'msition. a lower eleeu'erle and CHARLES A. BARNARD. 

